Posts Tagged ‘krill’

The swell was up and the rain in and out on Tuesday, but our ichthyology class braved it all for our class cruise in Monterey Bay. The Point Sur, MLML’s largest research vessel, was loaded with our class, an invertebrate zoology class from San Jose State, and various scientists from the Monterey Bay Aquarium and the Monterey Bay Aquarium Research Institute (incluing Kyra Schlining, featured in our alumni profiles!). We were all on a treasure hunt of sorts – ready to dip our big nets in the water and see what kind of fish and invertebrates would come up. It was anyone’s guess.

The crew hauls in the net, while a rainbow offsets the less-than-ideal weather (photo: E. Loury)

Like most cruises, there was a lot of downtime – waiting to get to our trawl location, waiting for the net to go out (about half an hour to reach our desired depth of 900 m!), waiting while the net dragged along catching things, waiting for it to come back in… But just trying to hold on to your balance (and your lunch) can be keep you plenty occupied on a rolling boat. It was a rough day for the faint of stomach, which I’m sure left many pondering Amanda’s timeless question: “Can I still become a marine biologist even if I get seasick?” The short answer is yes – but it’s certainly not always fun. Or pretty, for that matter.

What a find! Bottling up a squid (photo: E. Loury)

Our first trawl came up empty, because the net didn’t make it to the sea floor where it was designed to sample. But our second trawl of the midwater brought up a whole slurry of things to pick through and distract us from our queasiness. We huddled around tubs sloshing with a bright red soup of krill, the choice food of many whales, birds and fish. These little critters like small shrimp and are called euhpausiids. Lots of other interesting things were floating in the mix – the visiting scientists scooped up some squid, little jellyfish, and other gelatinous blobs. The fish class picked out the various myctophids, or lanternfish, which are little, black, deepwater fish that have a line of glowing photophores along their sides.

Some shiny myctophids, or lantern fish, from the deep (photo: E. Loury)

We sifted though the animals that lived in the water that surrounded us, down at depths we could scarecly comprehend. It was a rare chance to pluck them from their hard-to-access homes and bring them to our world of the surface, where we could poke, stare, and try to understand.

June 2, 2008. Dutch Harbor, Alaska and the R/V Oscar Dyson – We arrived in Dutch Harbor very late, indeed. I think it was after 1 am when I finally unlocked the door to my room. Outside, the dusky, midsummer light of an Aleutian evening was still slowly fading in the fog. I closed the curtains and sank happily into bed.

Boats amid mountains in Dutch Harbor, Alaska (photo by NMJ)

In the morning, I had just a couple hours free to take a stroll around Dutch Harbor, but I’ll be back again more than once this season; like many of the commercial fishing vessels, most all the research ships doing work in the Bering Sea must stop to exchange supplies or crew members in Dutch. This is a working town, in the truest sense. And, although it’s surrounded by beautiful wilderness, Dutch Harbor itself doesn’t see too many tourists!

Nonetheless I am fascinated and engaged by the sort of raw beauty that can be found in the industry of humankind. Although Dutch Harbor has gained an outsized, ribald reputation, I find it is also earnest, industrious, and indomitable. There is a certain honesty in the worn deck lines, rusty rails, towers of shipping containers, and acres of crab pots: This is how fish is brought to your dinner plate.

May 25, 2008. Moss Landing, California – The Bering Sea is a long way from Moss Landing, California. It’s a long way from most anywhere, actually. To begin my summer of field work, I must first fly from San Francisco, California to Seattle, Washington. In Seattle I will change planes and fly to Anchorage, Alaska. From Anchorage I’ll catch a small propeller plane and fly low over the mountains, glaciers, and the vast wilderness of Southwest Alaska to stop briefly in King Salmon, where we will refuel, and then continue on out along the foggy Aleutian Island chain to land in Dutch Harbor, Alaska. I will then board a research vessel that will motor for fifteen hours out into the Bristol Bay portion of the Bering Sea and there, at last, I will begin my work. It will probably take me three long days.

Map of the Bering Sea near Alaska (NOAA)

Humans are not the only animals that eat fish, of course! Seabirds flock by the millions to feed on fish in the Bering Sea, and also on energy-rich krill (tiny crustaceans, similar to a shrimp). These krill grow to become so numerous in summer that they form dense undersea clouds that can stretch for miles. Krill, known to scientists as euphausiids, are eaten by fish; in fact, we feed them to our own pet goldfish, in dried and flaked form! They are also the favorite food of many whales, which use their thick baleen plates to strain these tiny creatures from the water in huge, lunging mouthfuls.

Birds and whales feed together in Alaska

Because they like to eat similar kinds of food, whales and seabirds can oftentimes be seen congregating to feed together in productive areas that contain especially large amounts of fish and euphausiids. Such places are usually characterized by turbulence and the mixing of cold(er) and warm(er) ocean water. What is it about the turbulent combination of cold and warm water that attracts the euphausiids and fish?

During the next two months I will spend most of my time on the ocean. I will be taking special interest in these foraging hotspots, trying to learn more about how seabirds find and exploit them.

If you’re interested in learning more, Nate recommends the following websites:

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